1. Field of the Invention
The present invention relates generally to functionalizing nanotubes to form improved polymer-nanotube composites and, more particularly, to a method for functionalizing carbon nanotubes with a polymerizable ligand formed using polymerizable groups, for example, vinyl or styryl groups, in combination with a polyaromatic molecule such as a polyaromatic hydrocarbon (PAH) for the purpose of achieving significant improvements in the properties of a polymer-nanotube composite due to improved dispersion and chemical bonding between the polymer matrix and the nanotube itself.
2. Description of Related Art
Sustaining habitation on the moon, or any other planet, will require light weight, high strength structures that protect against both radiation and particulates. Chemical synthesis techniques to enable strong bonding between carbon nanotubes and polymers to form improved polymer-nanotube composites, technology which could be used for this application, are needed.
Polymer properties such as electrical conductivity have been shown to be enhanced by incorporating therein a combination of carbon fibers or carbon nanotubes (CNTs). Additionally, CNTs have been shown to prevent delamination and provide structural stability in polymer composites. Because CNTs have uniquely high strength to mass ratio, intrinsic light weight, thermal conductivity, electrical conductivity, and chemical functionality, and, as noted, have been shown to prevent delamination and provide structural stability in polymer composites, they can impart these properties to polymers when effectively combined therewith.
Though CNTs have extraordinary mechanical properties, their ability to strengthen polymers and epoxies is limited by the strength of interfacial bonding. As a result, when incorporated into polymeric resin without cross-linking or functionalization, they lack the ability to transfer loads across the structure.
CNTs can be functionalized via covalent or non-covalent bonding, to either the ends of the nanotubes or to the sidewalls. Covalent functionalization often requires beginning with modified tubes, such as fluorinated nanotubes, or with purified tubes where defect sites in the CNTs are produced by oxidation. Because these modifications often result in the disruption of the bonds along the tubes themselves, covalent functionalization can degrade the mechanical and electrical properties of the nanotubes and, thus, is not ideal for all applications.
Therefore, the present invention has been made in view of the above problems, and it is an objective of the present invention to provide a method for functionalizing carbon nanotubes using polymerizable ligands and to form improved polymer-nanotube composites utilizing the functionalized nanotubes.